<filter name='no-mac-spoofing' chain='mac' priority='-800'>
  <uuid>55880949-c29e-4829-b663-c38f234474dc</uuid>
  <rule action='return' direction='out' priority='500'>
    <mac srcmacaddr='$MAC'/>
  </rule>
  <rule action='drop' direction='out' priority='500'>
    <mac/>
  </rule>
</filter>

